I don't care about the firefox issue, because probably it can't be fixed.
But if you take a look to
Provincia Bergamo with firefox, you'll see that there is a conflict between ari slider and the menu.
The ari slider's position is set as "relative", but it appears on the right of the menu, and so the menu doesn't work.
THE QUESTION IS:
How can I set a custom margin for the ari slider I want?
Because I found a "base.css", but by changing the parameters every slider was affected by the modifies.
The site is builded on the Yoo_nano theme.
Thank you